Do Probiotics Help with Anxiety and Depression?

Okay, if you haven’t heard all the fanfare for probiotics from watching TV commercials, visiting your local grocery store, or even reading my blog posts, then you might be asking yourself, what are probiotics? As I’ve previously posted, probiotics are essentially dietary supplements or functional foods that contain potentially beneficial bacteria or yeast.

Research suggests that probiotics may have beneficial effects at preventing traveler’s diarrhea, treating allergic rhinitis, and reducing gastrointestinal symptoms. Recently, Canadian researchers from Toronto, published a study in the journal, Gut Pathogens, on the effects of probiotic cultures on the emotional symptoms in Chronic Fatigue Syndrome (Rao et al, 2009). Chronic Fatigue Syndrome (CFS) is a complex illness with no clearly understood etiology or specific cause. Emotional symptoms of CFS are most commonly of an anxiety nature.

Probiotics for Chronic Fatigue Syndrome Study:

Patients with CFS in this study were randomized to receive 24 billion colony forming units of Lactobacillus casei strain Shirota (LcS) or placebo daily for 2 months. Researchers found a significant rise in both Lactobacillus casei as well as bifidobacteria in the stools of the intervention group. Additionally, the researchers found a significant decline in anxiety symptoms (Beck Anxiety Inventory) in those taking LcS (p=0.01).

Bottom line: Keep in mind that the results of this study are specific to this species/strain of probiotic. Participants in this study also suffered from chronic fatigue syndrome. More research is necessary to clarify the role of specific probiotics for relieving anxiety symptoms.

I just came across your site, and I really love the facts you have on here. Thanks for all the references. It’s really interesting to know that pro-biotics can reduce anxiety. Does this happen with non-CFS sufferers as well?

Hi Jill, that’s a fair question. For this study, the test subjects were patients with CFS and had anxiety symptoms as well. At this point, research on probiotic use for anxiety prevention is still quite new. I’ve came across at least one more study recently on this topic, but more research is still necessary to make that type of recommendation.